New guidance is being developed for conducting risk assessment and management in the water and wastewater sectors. The guidance is based on the Risk Analysis and Management for Critical Asset Protection, or RAMCAP™, methodology. RAMCAP is a process for evaluating consequences, vulnerability and risks due to terrorism and natural hazards. RAMCAP was developed by the ASME Innovative Technologies Institute, LLC, to facilitate the comparison of risks among assets within a sector and across multiple sectors by employing a common terminology and standardized measurement metrics. RAMCAP is the methodology specified in the National Infrastructure Protection Plan (NIPP) for use in cross-sector comparison. It will provide essential, quantitative information to government and utility decision makers about consequences and vulnerabilities to terrorist threats, measured in dollars, fatalities and injuries, and qualitative information about impact on military readiness, public confidence, etc. RAMCAP is designed to aid decision support processes that lead to reduced risks and enhanced resilience of critical infrastructures. This paper describes a project, sponsored by the Department of Homeland Security in coordination with the Environmental Protection Agency, to develop RAMCAP guidance for the water and wastewater sectors.